This invention is directed to video monitors useful with relatively inexpensive computer systems.
The development of the low cost microprocessor created the portable, inexpensive computer market which is bringing the benefits of computer technology to a large body of non-technically educated people. The equipment may be used with existing television receivers or with separate, generally dedicated, video monitors. A video monitor is essentially a television receiver without the capability of receiving broadcast radio frequency signals. The available portable computers either have a direct video output for suplying video signals at baseband frequency to the video input of a monitor, or a radio frequency (RF) output for supplying modulated signals at VHF frequency for connection to the VHF television antenna terminals of a television receiver through an appropriate switch. Commonly, frequencies corresponding to VHF channels 3 and 4 are used.
There has been an equally rapid expansion of the video monitor market. Yet, most monitors, with their baseband video input circuitry, aren't compatible with computer equipment having RF outputs. Presently the owner of such computer equipment must seek a monitor (or television receiver) having an input that will accept the output of his computer. As the required level of technical sophistication of computer users diminishes the need for a universal monitor to function with either type of computer output increases. Thus it would be of benefit to the art to have video monitors available with a common input connection capable of selective operation, automatically, with computer devices producing basband video signals or video signals modulated on VHF channel 3 or 4 frequencies.